From bc01637a80f5b670bd70a0279d3f93fa8de1c96d Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 12 Sep 2012 13:26:55 +0300 Subject: [PATCH] digsig: add hash size comparision on signature verification When pkcs_1_v1_5_decode_emsa() returns without error and hash sizes do not match, hash comparision is not done and digsig_verify_rsa() returns no error. This is a bug and this patch fixes it. The bug was introduced in v3.3 by commit b35e286a640f ("lib/digsig: pkcs_1_v1_5_decode_emsa cleanup"). Cc: stable@vger.kernel.org Signed-off-by: Dmitry Kasatkin Signed-off-by: Linus Torvalds --- lib/digsig.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/lib/digsig.c b/lib/digsig.c index 286d558033e2..8c0e62975c88 100644 --- a/lib/digsig.c +++ b/lib/digsig.c @@ -163,9 +163,11 @@ static int digsig_verify_rsa(struct key *key, memcpy(out1 + head, p, l); err = pkcs_1_v1_5_decode_emsa(out1, len, mblen, out2, &len); + if (err) + goto err; - if (!err && len == hlen) - err = memcmp(out2, h, hlen); + if (len != hlen || memcmp(out2, h, hlen)) + err = -EINVAL; err: mpi_free(in); -- GitLab